Minutes, Mils And
Impatient Beasts

As the trigger broke, the slope gave way. My bullet sailed a foot high as I wind-milled like Charlie Chaplin on ice to keep my feet. The elk, 40 steps off, gawked.

Having muffed shots even closer, I shun long pokes. Shooters hurling rocket-shaped bullets into the hazy blue must ponder what we crouched in the thickets can ignore: Gravity. Minutes. Mils. And the patience of the wild.

The instant your bullet leaves the muzzle, gravity presses it toward earth at an accelerating rate of 32.17 feet per second. Given a 200-yard zero, bullets from some frisky hunting rounds land 18″ to 20″ low at 400. If your range estimate there is within 5 percent of actual, hold-over should keep shots in the vitals.

Gravity is implacable. It demands compensation. A 168-gr. BTHP leaving a .308 at 2,700 fps falls 144″ at 700 yards. Twelve feet! Over the next 50 yards, it drops another 20″! Charitably, gravity varies not in force or direction. For any distance, compensation needn’t change until wide swings in air temperature or density change drag.

Like an MOA, a mil (shorthand for milliradian) is an angular measure. A circle has 360 degrees, or 2pi radians. A radian is 57.32 degrees. A mil spans about 3.6″ at 100 yards. So each 0.1-mil click on a W/E dial moves impact 1 cm at 100 meters. On most reticles that mirror the standard U.S. Military MIL-dot, the space between dots on a crosswire is equal to one mil. To find the range with this reticle, divide target height in mils at 100 yards by the number of spaces it occupies and you get range in hundreds of yards. Example: A deer 3 feet tall (10 mils at 100 yards) appears to stand two dots high: 10/2 = 5. The deer is 500 yards away. You can also divide target size in yards by the number of mils subtended, then multiply by 1,000 to get range in yards: 1/2 x 1,000 = 500.

This math works on a first-focal-plane scope at any power magnification. On more-common and less-expensive second-focal-plane scopes, it only works at the highest power magnification. This highlights the advantages of a first-focal-plane scopes where dot spacing doesn’t change relative to the target regardless of magnification.

But what if that deer scrams while you sharpen your pencil? Trajectory-matched dials put you on target fast! I first used GreyBull Precision dials on a Leupold 4.5-14x but now several scope-makers list similar types such as the Leupold CDS. Each dial is cut and scribed to track a specific trajectory, defined by the bullet’s speed and ballistic coefficient. Then, instead of doing math, you index the dial number matching the range in yards, aim and fire! Using a GreyBull dial on a Marlin lever rifle, I fired prone from 100, 200, 300, 400, 500 and 600 steps and, with center holds, put all six shots within 4 vertical inches.

Of course, no matter the distance, or how precise your dial or computations, you must control the rifle better than I did assailing that elk.

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